Lever type connector assembly

Abstract: This invention simplifies a process of attaching a torsion coil spring 6 to an arm 22 of a lever 21. Each arm 22 of the lever 21 is provided on its inner face with a ring slot 25 formed around a bearing hole 23 for accommodating a ring portion 6a of the torsion coil spring 6 and a pair of holding slots 26 and 27 communicated with the ring slot 25 for accommodating end portions 6b and 6c. A raised guide 29 is formed on the inner face of the arm 22 near an outer edge of the holding slot 27. The raised guide 29 has a ramp face 30 which continuously increases in height approaching the holding slot 27 and a precipice 33 contiguous to the outer edge of the slot 27. The arm 22 of the lever 21 may be provided on its inner face with a circular arc tool slot 32 having a certain depth and extending from an end face of the arm 22 across a cam groove to the holding slot 27.

Description: This invention relates to a lever type connector assembly which interconnects and separates connectors by utilizing a cam action and more particularly to a lever type connector assembly in which a torsion coil spring for rockably biasing a lever to a given initial position is temporarily attached to one of the connectors. A lever type connector assembly has an advantage of interconnecting and separating connectors by a small force and particularly can be applied to multipole connectors. For convenience of explanation, a conventional lever type connector assembly will be explained below by referring to drawings. Figure 7 is an exploded perspective view of a conventional lever type connector assembly. Figure 8 is a perspective view of a lever shown in Figure 7, illustrating a torsion coil spring mounted on a side plate of the lever. Figure 9 is a perspective view of a female connector housing shown in Figure 7. Figure 10 is a fragmentary cross sectional view of the housing and lever shown in Figure 7, illustrating a position of which an end of the torsion coil spring engages with the housing. Figure 11 is a perspective view of a conventional torsion coil spring. Figure 12 is a fragmentary enlarged perspective view of the lever shown in Figure 8. Figure 13 is a cross sectional view of the lever shown in Figure 8, illustrating a process of attaching the torsion coil spring to the lever. Figure 14 is a longitudinal sectional view of the lever, illustrating a process of attaching an end of the torsion coil spring into a holding slot in the lever. An example of a conventional connector housing assembly, as shown in Figure 7, includes one (female) connector housing 1, a lever 3 mounted rotatably on a pair of support axles 4 on the housing 1 and having cam grooves 3a, and the other (male) connector housing 2 having a pair of cam followers 5. The pair of connector housings 1 and 2 are coupled to and detached from each other when the lever 3 is turned about the axles 4 to move the cam followers 5. In the above lever type connector assembly, in order to bias the lever 3 to a given rotary direction, a torsion coil spring 6 shown in Figure 14 is coupled to the lever 3 and female connector housing 1, as shown in Figures 8 to 10. At this time, a ring portion 6a of the spring 6 (Figure 11) is disposed around a bearing hole 3b and on an inner face of a side plate or arm 22a of the lever (see Figure 8), an end portion 6b of the spring 6 engages with the inner face of the arm 22a (see Figure 8), and the other end portion 6c of the spring 6 engages with a projection la on an outer face of the connector housing 1 (see Figures 9 and 10). Upon constructing the above lever type connector assembly, after fitting the ring portion 6a of the torsion coil spring 6 on the support axle 4 on the connector housing 1, one end portion 6b of the spring 6 is locked on a part of the lever 3 and the other end portion 6c of the spring 6 is locked on the projection la on the connector housing. This requires very difficult work and is inefficient. In order to avoid such difficult constructing work, the present applicant has proposed a lever type connector assembly in which the lever is provided with a pair of holding slots which accommodate opposite end portions of the torsion coil spring with it being biased, and in which one end portion of the spring accommodated in one holding slot is transferred from the slot to the connector housing after mounting the lever on the housing (Japanese Utility Model Public Disclosure No. 6-11270). According to this assembly, it is possible to greatly facilitate the work of mounting the lever on the connector housing, since the torsion coil spring is accommodated in the holding slots beforehand and the torsion coil spring on the lever does not interfere with the connector housing upon mounting the lever on the housing. However, although the above assembly enhances a work of mounting the lever on the connector housing, the work of attaching the torsion coil spring to the lever had to be improved. That is, in order to attach the torsion coil spring 6 shown in Figure 11 to the side plate 22a of the lever 3, the side plate 22a is provided in the inner face with a pair of holding slots 7 and 8 which receive opposite end portions 6b and 6c of the torsion coil spring 6 with the spring 6 being biased, as shown in Figures 12 and 13. First, one end portion 6b of the spring 6 is inserted into one holding slot 7 and the other end portion 6c is pushed and turned by a tool pin similar to an end of a ball pen to insert the end portion 6c into the other holding slot 8. At this time, since the other end portion 6c of the torsion coil spring 6 applies an elastic force to the tool pin 9, the tool pin 9 must be moved carefully so that the portion 6c does not leap over the tool pin 9 on account of its elastic force. Then, as shown in Figure 14, when the end portion 6c is moved near the other holding slot 8, a distal end of the tool pin 9 must apply a downward force in addition to a forward force to the end portion 6c to push it into the other holding slot 8. Although such operation is easier than a conventional operation of mounting the lever on the connector housing while locking the torsion coil spring 6 on both of the lever and the connector housing, the former operation still requires skilful work and results in inefficiency. In Figures 12 and 13, a reference number 10 is a tool aperture through which the tool pin 9 passes so that it pushes the other end portion 6c of the spring 6 in the other holding slot 8 towards the projection la on the connector housing 1. An object of the present invention is to provide a lever type connector assembly in which a process of attaching a torsion coil spring to a lever beforehand can be simplified and an entire assembling work of connectors can be greatly improved. In order to achieve the above object, a lever type connector assembly comprises: a pair of first and second connector housing; a lever having a pair of arms on opposite ends and mounted rotatably on said first connector housing, said arm being provided on its inner face with a cam groove which engages with a cam follower on said second connector housing, said first and second connector housings being connected with and detached from each other when said lever is turned to move said cam follower; torsion coil springs having a central ring portion and a pair of first and second end portions extending from said ring portion, each torsion coil spring being coupled to said first connector housing and said arm of said lever to bias said lever toward a given rotary direction, said arm of said lever being provided on its inner face with a central ring slot adapted to accommodate said ring portion of said central ring portion and a pair of first and second holding slots communicated with said central ring slot and adapted to accommodate said first and second end portions of said spring with said spring being biased; characterised in that said assembly is provided with assuring means comprising a raised guide which is formed near an outer edge of said second holding slot said raised guide comprising a ramp face which continuously increases in height approaching said second holding slot and a precipice contiguous to said outer edge of said holding slot and an aperture is formed in the arm of the lever, adapted so that a tool pin can be inserted through the aperture to transfer the second end portion of the spring from the lever to said first connector housing. The torsion coil spring is mounted on the arm of the lever by the following processes. The first end portion of the torsion coil spring is inserted into the first holding slot and the second end portion of the spring is moved toward the second holding slot while biasing the spring. When the second end portion approaches the second holding slot, it rides on the ramp face of the raised guide to generate a downward elastic force. When the second end portion rides over the ramp face and reaches the precipice, it falls down into the second holding slot by its downward elastic force. After attaching the torsion coil spring to the lever, the lever is mounted on the first connector housing and the second end portion is pushed out of the second holding slot. The second end portion pushed out of the slot engages with the first connector housing so that the lever is biased toward the given rotary direction. As described above, according to the lever type connector assembly in which the raised guide is provided on the arm of the lever, since after the torsion coil spring is predeterminedly attached to the lever, the lever can be mounted on the first connector housing without handling the spring, the work of mounting the lever on the first connector housing can be greatly facilitated. Further, since the ramp face of the raised guide causes the second end portion of the spring to be inserted into the second holding slot by the downward elastic force, the work of attaching the torsion coil spring to the lever can be greatly enhanced and the entire work of constructing the connector assembly can be greatly improved. Figure 1 is an exploded perspective view of a lever type connector assembly, illustrating a position in which a female connector housing is separated from a male connector housing on which a lever is mounted; Figure 2 is a perspective view of the male connector housing, illustrating a position in which the lever is detached from the male connector housing; Figure 3 is a cross sectional view of a lever in a first embodiment of a lever type connector assembly in accordance with the present invention; Figure 4 is an enlarged longitudinal sectional view of a raised guide; Figures 5A to 5C are cross sectional views of the lever in the first embodiment, illustrating processes of attaching a torsion coil spring to the lever; Figure 6 is a sectional view similar to Figure 4, illustrating a process of attaching an end of the torsion coil spring into a holding slot in the lever; Figure 7 is an exploded perspective view of a conventional lever type connector assembly; Figure 8 is a perspective view of a lever shown in Figure 10, illustrating a torsion coil spring mounted on a side plate of the lever; Figure 9 is a perspective view of a female connector housing shown in Figure 7; Figure 10 is a fragmentary cross sectional view of the housing and lever shown in Figure 7, illustrating a position at which an end of the torsion coil spring engages with the housing; Figure 11 is a perspective view of a conventional torsion coil spring; Figure 12 is a fragmentary enlarged perspective view of the lever shown in Figure 8; Figure 13 is a cross sectional view of the lever shown in Figure 8, illustrating a process of attaching the torsion coil spring to the lever; and Figure 14 is a longitudinal sectional view of the lever, illustrating a process of attaching an end of the torsion coil spring into a holding slot in the lever. An embodiment of a lever type connector assembly in accordance with the present invention will be explained below by referring now to the drawings. Figures 1 through 6 show an embodiment of the lever type connector assembly of the present invention. A male (first) connector housing 11 is open at a front side end. A plurality of male terminals not shown are disposed in the interior of housing 11 with the terminals extending toward the front side end. The male connector housing 11 is provided on its opposite sides with support axles 12 disposed coaxially for bearing a lever 21 described hereinafter. On the other hand, a female (second) connector housing 40 has a shape and a size suitable for being received in a front opening in the male connector housing 11. A plurality of female terminals not shown are disposed in the interior of the female connector housing with the terminals extending toward a front side end. When the male and female connector housings 11 and 40 are completely interconnected, the male and female terminals are electrically connected. The female connector housing 40 is provided on opposite sides with cam followers 13, 13 which cooperate with the lever 21 to interconnect the housings 11 and 40. The lever 21 is provided on opposite ends with side plates or arms 22, 22 extending in parallel with each other and generally formed into a U-shaped block. The arms 22, 22 of the lever 21 are provided with bearing holes 23, 23 which are disposed coaxially. The lever 21 is mounted on the male connector housing 11 by inserting the support axles 12, 12 into the bearing holes 23, 23. The arms 22, 22 are provided on inner faces with cam grooves 24, 24 which extend from one end faces to inner parts of the arms. A width of the cam groove 24 is equal to or larger than a diameter of the bearing hole 23. Upon coupling the female connector housing 40 to the male connector housing 11, the lever 21 is mounted on the male connector housing 11, the housings 11 and 40 are opposed to each other at their front sides and approached to each other, the cam follower 13 on the female connector housing 40 is fitted in an end of the cam groove 24 in the lever 21, the lever 21 is turned about the support axle 12 to pull the cam follower 13 into the cam groove 24, the lever 21 is further turned to forcibly approach the connector housings 11 and 40 to each other by a "lever action", and the connector housings 11 and 40 are finally interconnected. A torsion coil spring 6 is disposed between the lever 21 and an engaging projection 14 (see Figure 2) in order to bias the lever 21 in a given rotary direction relative to the male connector housing 11. The torsion coil spring 6 is a common shape shown in Figure 11 and has a ring portion 6a formed by winding a spring wire into a coil and a pair of first and second end portions 6b and 6c extending tangentially from the ring portion 6a. The legs 6b and 6c extend straightly by an angle of 180° therebetween as shown in Figure 11 when no external force is applied to the spring 6. In order to mount the torsion coil spring 6 on the lever 21, the arm 22 of the lever 21 is provided in its inner face with a ring slot 25 around the bearing hole 23 for accommodating the ring portion 6a and a pair of first and second holding slots 26 and 27 communicated with the ring slot 25 for accommodating the portions 6b and 6c, as shown in Figure 3. An angular distance between the holding slots 26 and 27 is set to be, for example, 60° or so. The portions 6b and 6c are received in the holding slots 26 and 27 by approaching the portions 6b and 6c with each other against the elastic force of the torsion coil spring 6. An aperture 28 is formed in a middle portion of the (second) holding slots 27 in the arm 22 of the lever 21. The aperture 28 permits a tool pin not shown to eject the second end portion 6c from the second holding slot 27 by inserting the tool pin into the aperture. As shown in Figures 4 and 5A to 5C, the arm 22 is provided near an outer edge of the first holding slot 27 having the aperture 28 in the inner face with a raised guide 29. The raised guide, as shown in Figures 5A to 5C, has a ramp face 30 which continuously increases a height with approaching to the second holding slot 27, a flat top 31 and precipice 33 contiguous to the outer edge of the second holding slot 27. Next, a process of constructing the first embodiment of the lever type connector assembly will be explained below. Before the lever 21 is mounted on the female connector housing 11, the torsion coil spring 6 is mounted on the lever 21. The first end portion 6b of the spring 6 is received in the first holding slot 26 and the central ring portion 6a is received in the ring slot 25. The spring 6 is free of load, so that an angle between the end portions 6b and 6c is about 180°. Accordingly, the second end portion 6c is spaced from the second holding slot 27, as shown in Figure 5A. Then, an elongated tool pin T engages with the second end portion 6c and pushes it against its elastic force to slide it on the inner face of the lever 21 toward the second holding slot 27 in a direction shown by an arrow in Figure 5A. As shown in Figure 5B, when the second end portion 6c of the torsion coil spring 6 reaches near the second holding slot 27, the portion 6c encounters the raised guide 29 and receives an upward reaction force by the ramp face 30. Consequently, the second end portion 6c moves on the ramp face 30 while the portion slides upwardly on the tool pin T (see Figure 6). When the second end portion 6c reaches the flat top 31 of the raised guide 29, an upward elastical deformation of the second end portion 6c becomes maximum. When the portion 6c reaches the precipice 33 through the flat top 31, the portion 6c falls into the second holding slot 27 by its elastical force as shown by a two-dot-chain line in Figure 6. In the first embodiment, the second end portion 6c of the torsion coil spring 6 is naturally accommodated in the second holding slot 27 only by pushing the portion 6c toward the slot 27 by the tool pin T. Accordingly, it is possible to readily accommodate the portion 6c in the slot 27 without pushing it into the slot 27 in the conventional assembly. After the torsion coil spring 6 is mounted on the lever 21, the support axles 12 of the male connector housing 11 are fitted in the bearing holes 23 in the lever 21, so that the lever 21 is mounted on the connector housing 11. At this time, since the lever 21 can be mounted on the connector housing 11 in spite of existence of the spring 6, such mounting operation can be simplified. When the tool pin is inserted into the aperture 28 in the lever 21 to push the second end portion 6c of the spring 6, the second end portion 6c is ejected from the second holding slot 27 and engages with the engaging projection 14 on the male connector housing 11. Consequently, since the first end portion 6b of the spring 6 is still received in the first holding slot 26 while the second end portion 6c engages with the projections in the male connector housing 11, the lever 21 is biased toward the given rotary direction by the elastic force of the spring 6. According to the embodiment shown, since the lever 21 on which the torsion coil spring 6 is mounted beforehand can be mounted on the connector housing 11, the mounting operation of the lever can be greatly simplified and, in addition, the torsion coil spring 6 can be readily attached to the lever 21 by displacing the second end portion 6c in a direction by means of the tool pin. Generally, the constructing operation of the connector assembly can be considerably improved. It should be noted that the present invention is not limited to the first embodiment but can be altered by, for example, the following forms: (a) Although the bearing hole 23 passes through the arm 22 in the embodiment, the hole may be formed into a blind hole which is open not in the outer face but in the inner face; or (b) Although the lever 21 is mounted on the male connector housing 11 in the embodiment, the lever may be mounted on the female connector housing and the cam follower may be provided on the male connector housing.

Claims: A lever type connector assembly comprises: a pair of first and second connector housings (11,12); a lever (21) having a pair of arms (22) on opposite ends and mounted rotatably on said first connector housing, said arm being provided on its inner face with a cam groove (24) which engages with a cam follower (13) on said second connector housing, said first and second connector housings being connected with and detached from each other when said lever is turned to move said cam follower; torsion coil springs (6) having a central ring portion (6a) and a pair of first (6b) and second (6c) end portions extending from said ring portion, each torsion coil spring being coupled to said first connector housing and said arm of said lever to bias said lever toward a given rotary direction, said arm of said lever being provided on its inner face with a central ring slot (25) adapted to accommodate said ring portion of said central ring portion and a pair of first and second holding slots (26, 27) communicated with said central ring slot and adapted to accommodate said first and second end portions (6b, 6c) of said spring with said spring being biased; characterised in that said assembly is provided with assuring means comprising a raised guide (29) which is formed near an outer edge of said second holding slot (27) said raised guide comprising a ramp face (30) which continuously increases in height approaching said second holding slot and a precipice (33) contiguous to said outer edge of said holding slot and an aperture (28) is formed in the arm of the lever, adapted so that a tool pin can be inserted through the aperture to transfer the second end portion (6c) of the spring (6) from the lever (21) to said first connector housing.

Inventors: KATSUMA TAKATOSHI, KATSUMA, TAKATOSHI, KATSUMA, TAKATOSHI, C/O SUMITOMO WIRING SYST., LTD
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1994
Main classification: H01R13
IPC codes: H01R13